Academic literature on the topic 'Mottled enamel. Fluorosis, Dental'

ABSTRACT High intake of fluoride causes developmental disturbances of tooth enamel leading to dental fluorosis. It produces mottling of enamel and its occurance depends upon the quantity of fluoride ingested and the stage of tooth development. Esthetic management of mottled teeth is planned according to the severity of discoloration and the extent of surface aberrations. A combination of different techniques makes the teeth lighter in shade with a smoother surface. This case report describes the management of fluorosed teeth which is discolored and pitted on the surface by minimally invasive procedures. How to cite this article Nair R, Das AN, Kuriakose MC, Praveena G. Esthetic Rehabilitation of Teeth with Dental Fluorosis. Int J Prosthodont Restor Dent 2014;4(1):11-13.

Aim: The aim of this review is to discuss various effects of fluoride on hard and soft tissues of the periodontium and its importance in human life. Background : Fluoride is an essential element for life and is one of the trace elements normally present in the body. It is abundant in the environment and the main source of fluoride to humans is drinking water. Fluoride gets accumulated in hard tissues of the body and has been known to play an important role in mineralization of bone and teeth. The behaviourof fluoride ions in the human organism can be regarded as that of double-edged sword. In small amounts, it is known to have beneficial effects on dental health. On the other hand, excessive chronic intakes can result in adverse effects including the development of dental fluorosis in children and/or skeletal fluorosis in both children and adults. Although effect of fluoride on caries has been discussed in painstaking details through various studies but the effect of fluorosis on the periodontium yet remains in shadow. Review Results : Dental fluorosis is a developmental disturbance of dental enamel, caused by successive exposures to high concentrations of fluoride during tooth development, leading to enamel with lower mineral content and increased porosity. Even after continuing with the age old logic of structural changes that take place in mottled enamel it can be said with scientific plausibility that this factor of surface roughness can or must influence some of the variables in this multifactorial disease of periodontitis. This surface roughness is conducive for the bacteria to survive as well as make it difficult for scaling and root planing in fluorosed teeth. This could also jeopardize the effectiveness of the regular oral hygiene procedures. Conclusion : Dental fluorosis is not only a cosmetic problem that impairs social well-being but also affects the oral health related quality of life. Fluorosis continues to be an important problem, both for the affected individuals and for public health. More and more areas are being discovered regularly that are affected by fluorosis in different parts of the country. But ultimate solution for this fluoride menace remains to be the principal of Precaution is better than cure. Clinical Significance : Considering the role of fluorosis on hard and soft tissues and all the risk factors of periodontitis, fluorosis can be recommended strongly as an environmental risk factor for periodontitis. To be defined as one of the etiological (environmental) agent of periodontal disease requires further research studies with greater sample size from varying areas globally.

OBJECTIVE: To understand beliefs and attitudes about fluorosis among young people living in a rural area. METHODOLOGICAL PROCEDURES: Qualitative study consisting of semi-structured interviews with 23 adolescents with dental fluorosis, 14 teachers and three health authorities in the city of São Francisco, Southeastern Brazil, in 2002. Content analysis and social representation theory were applied. ANALYSIS OF RESULTS: The organoleptic characteristics of carbonates that affect groundwater (salty flavor, whitish coloration, and turbidity) associated with negative aspects of household use of this water are considered a cause of mottled enamel. Even after contact with researchers who investigated this phenomenon and helped find a solution for this condition, the local population is still unwilling to accept fluoride as the cause of the problem and does not fully agree to use water from other sources because they are afraid of the quality of water. CONCLUSIONS: Misperceptions of the causes of dental fluorosis and water treatment costs compromise the implementation of uncontaminated surface water supplies. Health education strategies are required in parallel with solutions for securing water supply in drought-ravaged areas.

The concentration of fluoride in drinking water is the major determinant of the prevalence and severity of dental fluorosis in a community. Fluorosis is more prevalent and discernible in permanent teeth than in primary teeth; the intensity can range from barely perceptible, whitish striations in enamel to confluent pitting and dark staining. The traditional belief is that fluorosis is produced only during the secretory stages of ameloblastic activity. Some recent reports suggest that the maturation stages of enamel development are as important as or even more important than the secretory stages as the time when fluorosis can be produced. The question of timing remains unresolved. Many questions also remain about general and individual physiologic variations in relation to susceptibility to dental fluorosis. Good criteria for differential diagnosis exist to distinguish dental fluorosis from non-fluoride enamel opacities. An increasing number of reports indicates that the prevalence of fluorosis may be increasing among children in fluoridated and non-fluoridated communities. Reasons for the increases may relate to misuse of dietary fluoride supplements, ingestion of fluoride toothpastes, or increasing amounts of fluoride in foods or the atmosphere. The intensity of the increased fluorosis is in the milder categories and is not generally unsightly. It should be recognized that a small amount of fluorosis may be an alternative to a greater prevalence of dental caries, a disease that may produce cosmetic problems and sequelae worse than those produced by fluorosis.

Enamel formation and quality are dependent on environmental conditions, including exposure to fluoride, which is a widespread natural element. Fluoride is routinely used to prevent caries. However, when absorbed in excess, fluoride may also lead to altered enamel structural properties associated with enamel gene expression modulations. As iron plays a determinant role in enamel quality, the aim of our study was to evaluate the iron metabolism in dental epithelial cells and forming enamel of mice exposed to fluoride, as well as its putative relation with enamel mechanical properties. Iron storage was investigated in dental epithelial cells with Perl’s blue staining and secondary ion mass spectrometry imaging. Iron was mainly stored by maturation-stage ameloblasts involved in terminal enamel mineralization. Iron storage was drastically reduced by fluoride. Among the proteins involved in iron metabolism, ferritin heavy chain (Fth), in charge of iron storage, appeared as the preferential target of fluoride according to quantitative real-time polymerase chain reaction, Western blotting, and immunohistochemistry analyses. Fluorotic enamel presented a decreased quantity of iron oxides attested by electron spin resonance technique, altered mechanical properties measured by nanoindentation, and ultrastructural defects analyzed by scanning electron microscopy and energy dispersive x-ray spectroscopy. The in vivo functional role of Fth was illustrated with Fth+/-mice, which incorporated less iron into their dental epithelium and exhibited poor enamel quality. These data demonstrate that exposure to excessive fluoride decreases ameloblast iron storage, which contributes to the defective structural and mechanical properties in rodent fluorotic enamel. They raise the question of fluoride’s effects on iron storage in other cells and organs that may contribute to its effects on population health.

It is now well-established that a linear relationship exists between fluoride dose and enamel fluorosis in human populations. With increasing severity, the subsurface enamel all along the tooth becomes increasingly porous (hypomineralized), and the lesion extends toward the inner enamel. In dentin, hypomineralization results in an enhancement of the incremental lines. After eruption, the more severe forms are subject to extensive mechanical breakdown of the surface. The continuum of fluoride-induced changes can best be classified by the TF index, which reflects, on an ordinal scale, the histopathological features and increases in enamel fluoride concentrations. Human and animal studies have shown that it is possible to develop dental fluorosis by exposure during enamel maturation alone. It is less apparent whether an effect of fluoride on the stage of enamel matrix secretion, alone, is able to produce changes in enamel similar to those described as dental fluorosis in man. The clinical concept of post-eruptive maturation of erupting sound human enamel, resulting in fluoride uptake, most likely reflects subclinical caries. Incorporation of fluoride into enamel is principally possible only as a result of concomitant enamel dissolution (caries lesion development). At higher fluoride concentrations, calcium-fluoride-like material may form, although the formation, identification, and dissolution of this compound are far from resolved. It is concluded that dental fluorosis is a sensitive way of recording past fluoride exposure because, so far, no other agent or condition in man is known to create changes within the dentition similar to those induced by fluoride. Since the predominant cariostatic effect of fluoride is not due to its uptake by the enamel during tooth development, it is possible to obtain extensive caries reductions without a concomitant risk of dental fluorosis.

Dental fluorosis is caused by ingesting too much fluoride while the teeth are developing. Poltava region belongs to Buchach fluorine hydrogeological province which ground waters are characterized by a high content of fluorine. Such districts as Myrgorod, Lubny, Gadyach, Globino, Mashivka, Shyshaky and Novy Sanzshary have fluoride concentration in drinking water from 2,5 tо 7 mg/l. It is known that the overdose of fluoride has deleterious effect on enamel development, generating a hypomineralized porous subsuperfacial enamel. Mild fluorosis transforms into moderate fluorosis with brown pigmentation over time and increasing the severity of fluorosis is associated with increasing the patient`s dissatisfaction. There are a few different ways that dental fluorosis can be treated. Local remineralisation therapy is the most careful way to reduce or eliminate fluorosis spots. Enamel microabrasion removes the outer porous enamel with pumice after it has been partly demineralized by the acid; topical fluoride that remineralized the enamel follows microabrasion. A teeth whitening can return teeth to their former glory in a single visit. Infiltration technique is the novel approach to fluorosis management which masks white spots. Veneers or crowns are the next option that restores teeth gleaming appearance. Unfortunately, previous reviews that have analyzed contemporary methods of fluorosis treatment didn’t determine their indications depending on the disease severity and the enamel maturation. Purpose of the study was to systematize the methods of dental fluorosis management offered last years and to determine the indications for their use depending on the severity of the disease and the maturity of the tooth enamel. Searching strategy for identification of scientific publications published between the years 2009 - May 2019 was conducted by reviewers independently through Google. The search strategy included keywords "dental fluorosis management", «teeth whitening», «teeth microabrasion», «infiltration for fluorosis treatment» and it was complementated by checking references of the relevant review articles and the eligible studies for additional useful publications. Over the last 10 years few articles were dealt with minerals, vitamins, adaptogens, antitoxicants prescription for fluorosis management. Such tooth pastes as «R.O.C.S» and «Novyi zhemchuh calcium» showed efficacy in local remineralisation therapy of fluorosis in children. Infiltration technique was used for mild fluorosis management and in combination with whitening for moderate fluorosis treatment in children. Different tooth whitening techniques were offered and only some of them include local remineralisation therapy that can stabilize clinical result. Carbamide and orthophosphoric acid were utilized for whitening of immature fluorosis teeth. Microabrasion in children's teeth was effective in combination with following fluoridation, for example Tooth Moose. Direct and indirect restorations are considered the treatment of choice for moderate to severe cases of fluorosis given the optimum aesthetics, wear resistance, biocompatibility, and long-term results. Whereas veneers and crowns are indicated in mature fluorosis teeth, choice of direct composite restorations doesn’t depend on tooth maturity. Treatment of fluorosis of various severities in children should include endogenous use of medicines that increase the enamel remineralisation. Local remineralisation therapy is indicated for mild fluorosis in immature teeth and for moderate fluorosis in combination with bleaching and microabrasion. Infiltration technique is recommended for mild fluorosis management and in combination with whitening for moderate fluorosis treatment in children. In the case of inefficiency of minimally invasive methods or severe fluorosis, direct or indirect restorations are conducted. Promising direction in fluorosis treatment is the development of new methods for fluorosis management, including general and local remineralization therapy, as well as infiltration technique.

ABSTRACT Objective To check knowledge of undergraduate dental students to make diagnosis of dental fluorosis with varying degrees of severity and choose its appropriate treatment. Methods Data were collected using a semi-structured questionnaire addressing knowledge of undergraduates based on ten images of mouths presenting enamel changes. Results Only three images were correctly diagnosed by most undergraduates; the major difficulty was in establishing dental fluorosis severity degree. Conclusion Despite much information about fluorosis conveyed during the Dentistry training, as defined in the course syllabus, a significant part of the students was not able to differentiate it from other lesions; they did not demonstrate expertise as to defining severity of fluorosis and indications for treatment, and could not make the correct diagnosis of enamel surface changes.

In June, 1978, the fluoride concentration in Hong Kong water supplies was reduced from 1.0 to 0.7 mg/ L. The objectives of this study were (1) to determine whether, as a result of this minor adjustment, a consequent reduction in the prevalence and severity of dental fluorosis came about, and (2) to determine whether dental fluorosis develops during enamel secretion and primary mineralization or during the maturation stage of enamel development. Dental fluorosis was assessed by Dean's community fluorosis index (CFI) on upper central incisors in 2382 children aged from 7 (exposed to 0.7 mg/L only) to 13 years. The children were selected from four districts served with drinking water by four different water treatment stations. Differences in the distributions of dental fluorosis scores across ages were significant in all districts. The susceptibility to fluoride was assessed statistically through a series of analyses whereby the fluoride concentration in the drinking water (both coincident with enamel secretion and periods of enamel maturation) was correlated with CFI. It was concluded (1) that CFI values were reduced following a minor adjustment to the fluoride concentration in drinking water, (2) that dental fluorosis develops during the maturation stage of enamel development, (3) that the development of dental fluorosis may occur over a period of 16 to 24 months, commencing from 12 to 32 months following enamel secretion, and (4) that Dean's index is a suitable instrument for monitoring the effects on dental fluorosis of minor adjustments to the fluoride concentration in drinking water.

The most appropriate and widely used source of drinking water for the rural populations of South Africa is groundwater. Pilot studies and surveys conducted by the Department of Water Affairs and Forestry (DW AF) indicated that there are a number of boreholes across the country that contain apart from fluoride, levels of nitrate, some heavy metals, total dissolved solids, sulphates and faecal coliform (in isolated regions) that could pose a health risk if the water is used for drinking purposes. Very few boreholes have been tested for heavy metals or toxic organic substances. However considering the levels of fluoride, in general, groundwater is of acceptable quality except for some provinces in which elevated levels of natural groundwater fluoride occurs. Very high levels of fluoride, >4 mg/l occur in some groundwater sources in all nine provinces of South Africa, especially in the Limpopo, North-West, Eastern Cape, Northern Cape, Western Cape and KwaZulu Natal provinces. A superficial inspection reveals that most of the local people in those areas suffer from dental fluorosis at varying degrees. The main aim of this study is to determine the distribution of the fluoride ion concentration levels in South African groundwater and the impacts thereof on dental health. The available data is used to assess the distribution of the various fluoride ion concentration levels in some national groundwater sources. Areas of particularly high or low fluoride levels are identified. Results from an epidemiological survey carried out by the National Department of Health (NDOH) are used concurrently with the fluoride data to determine the percentage morbidity of dental fluorosis in each area The results are compared in order to determine if any relationship exists between the occurrence of fluoride in drinking water and the incidences of dental fluorosis. Vegter's lithostratigraphy and the simplified geology of South Africa are used to interpret the results and assess the role of surface geology in the release and distribution of fluorides in groundwater. The role of other factors such as climate and the interactions of the fluoride ion and other water quality parameters in aqueous media are also assessed.
Dissertation (MSc (Water Utilization))--University of Pretoria, 2006.
Chemical Engineering
unrestricted

Orientador: Maria da Luz Rosario de Sousa
Tese (doutorado) - Universidade Estadual de Campinas, Faculdade de Odontologia de Piracicaba
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Resumo: Capitulo 1 - Objetivo: Conhecer as condições de saúde bucal dos escolares aos 12 anos de idade, em relação à carie dentaria e fluorose em Manaus-AM, que não tinha fluoretação daáagua de abastecimento público, no ano de 2003. Metodologia: Os dados do presente trabalho foram obtidos do Projeto SB Brasil 2003 (MS, 2004) que incluiu no estudo epidemiológico todas as capitais brasileiras. Foi realizada amostragem probabilística por conglomerados para a seleção das escolas e das crianças. Resultados: Foram examinadas 102 crianças de 12 anos das escolas publicas de Manaus. O CPO-D em Manaus (2003) foi de 3,20 (±3,93), sendo dentes cariados o maior componente do índice (54,5%). A prevalência de fluorose nos escolares foi de 8%. Conclusão: No presente estudo o CPOD encontrado não atingiu a meta da OMS para o ano de 2000 (escolares aos 12 anos - CPOD '< ou =' 3,0) e ficou distante de atingir a meta da OMS para 2010 (CPOD < 1,0), necessitando assim implementação de atividades preventivas e curativas para saúde bucal destes escolares, bem como constante monitoramento destas condições, e a utilização de um método coletivo de uso do fluoreto. A maioria dos escolares aos 12 anos estavam livres de fluorose (92%). Capitulo 2 - Objetivo: Verificar a prevalência das alterações de coloração de esmalte de caráter extrínseco bem como a sua relação com a qualidade da agua na cidade de Caapiranga/AM. Metodologia: Foram examinados 346 moradores da zona urbana do município que também responderam a um questionário de hábitos alimentares e autopercepção de saúde bucal. As residências foram as unidades amostrais, que foram sorteadas aleatoriamente.... Observação: O resumo, na íntegra, poderá ser visualizado no texto completo da tese digital
Abstract: Chapter 1 - Goal: Understand the oral health status of the 12 year old scholars in relation to dental caries and fluorosis in Manaus-AM, which has no fluoridation of public water supply in the year 2003. Methodology: The data in this paper was obtained from the SB Brazil Project 2003 (MS, 2004) that included, in this epidemiological study, all Brazilian capitals. Was performed by cluster random sampling for selection of schools and children, allowing the production of inferences. Results: We examined 102 12 year old children of public schools in Manaus. DMFT in Manaus (2003) was 3.20 (+ or - 3.93), and decayed teeth the largest component of the index (54.5%). The prevalence of fluorosis in children was 8%, and only 6 students had very mild fluorosis (5.88%) and 01 mild fluorosis (0.98%). Conclusion: In this study the DMFT found did not reach the WHO target for the year 2000 (school for 12 years - DMFT < or - 3.0) and was far from attaining the goal of WHO in 2010 (DMFT <1.0), thus requiring the implementation of preventive and curative oral health for these students, as well as constant monitoring of these conditions, and using a collective method of use of fluoride. Most of the 12-year-olds were free from fluorosis (92%). Chapter 2 - Purpose: To investigate the possible relationship of changes in tooth color of extrinsic character and water quality in the city of Caapiranga - AM. Methodology: 346 residents of the urban area were examined, who also answered a questionnaire on dietary habits and oral health perception. The homes were the sampling units and were randomly selected.... Note: The complete abstract is available with the full electronic digital thesis or dissertations
Doutorado
Saude Coletiva
Doutor em Odontologia

Enamel formation may be affected by genetic and environmental factors resulting in enamel defects such as developmental defects of enamel (DDE) and dental fluorosis. This 3 phase project investigated the influence of fluoride (F) exposure (intake and excretion), nutritional deficiencies, dental factors as well as other environmental factors and genetics on DDE and dental fluorosis among 4 and 8 year old Nigerian children. In Phase 1, dental examination for the presence of DDE, dental fluorosis and caries experience using the modified DDE index, Thylstrup and Fejerskov (TFI) and Dean’s indices and dmft/DMFT indices respectively was undertaken for 302 four-year-olds and 322 eight-year-olds and a parent/guardian questionnaire collected data on dental health and nutrition. In Phase 2, information and samples to estimate F intake and urinary F excretion of a sub-sample of 61-four- and 64 eight-year-olds was obtained. In Phase 3, a buccal mucosa swab was collected from the subsample for gene sequencing to determine the presence of Single Nucleotide Polymorphisms (SNP) in the COL1A2 gene. The prevalence of dental fluorosis, dental caries and DDE was 5.6%, 10.6% and 78.5% and 9.3%, 16.8% and 64.7% in the primary dentition of 4 and 8 year olds respectively while it was 29.8%, 7.5% and 67.1% respectively in the permanent dentition of 8 year olds. The Spearman correlation coefficient for severity of primary dentition dental fluorosis and drinking water F in 4 and 8 year olds was 0.12 and 0.15 respectively (p < 0.05); in the permanent dentition of 8 year olds it was 0.17 (p=0.002) for cooking water F and 0.28 (p=0.001) for drinking water F. The Pearson correlation coefficient for Total Daily F Intake (TDFI) and urinary F excretion was 0.41 (p=0.001) and 0.57 (p < 0.001) in 4 and 8 year olds respectively. Drinks, foods and toothpaste contributed 17%, 54% and 29% and 21%, 54% and 25% to TDFI among 4 and 8 year olds respectively. Fluoride toothpaste use, gender, drinking water F, cooking water F, exclusive breastfeeding, infant/childhood diseases, TDFI and Total Daily Fluoride Retention (TDFR) were statistically significant predictors of DDE and dental fluorosis (p < 0.05). The presence of SNPs CC and AC in the COL1A2 gene approached statistical significance as predictors for dental fluorosis (p=0.08). Enamel formation is vulnerable process, prone to many influences. The DDE and TFI indices provided a sensitive record to explore predictors for the presence of enamel defects and dental fluorosis in this young Nigerian population. Adoption of oral health and feeding habits which prevent excessive F exposure remain key principles to mitigate against these conditions.

Análise proteômica da matriz do esmalte nos estágios de secreção e maturação em camundongos susceptíveis ou resistentes à fluorose dentária, expostos cronicamente ao fluoreto através da água de beber. Os mecanismos pelos quais a ingestão excessiva de fluoreto (F) durante a amelogênese levam à fluorose dentária ainda não são precisamente conhecidos. Tem sido demonstrado que determinadas linhagens de camundongos são mais susceptíveis que outras à fluorose dentária, o que faz destas linhagens o modelo ideal para se estudarem os fenômenos moleculares envolvidos nesta patologia. No presente estudo, foi empregada uma abordagem proteômica para avaliar alterações na expressão de proteínas da matriz do esmalte dentário nos estágios de secreção e maturação, em duas linhagens de camundongos com diferentes susceptibilidades à fluorose (A/J, susceptível e 129P3/J, resistente). Camundongos de ambos os gêneros, representantes das linhagens 129P3/J (n=200) e A/J (n=200) foram distribuídos em dois grupos para cada linhagem, que receberam ração com baixa concentração de F e água de beber contendo 0 (controle) ou 50 mg/L F por 6 semanas. A concentração de F foi analisada no plasma e no esmalte dos incisivos. Para a análise proteômica, foi realizada a raspagem da matriz do esmalte dos incisivos, nos estágios de secreção e maturação. Para a extração das proteínas do esmalte, foram pesados 15 mg de pó da matriz do esmalte, aos quais foi adicionado 1 mL de tampão de lise contendo uréia 7 M, tiouréia 2 M, CHAPS 4 %, DTT 1 %, anfólitos carreadores 0,5 % pH 3-10 e um coquetel de inibidores de proteases. As proteínas do esmalte extraídas para cada grupo foram separadas pela técnica de eletroforese bidimensional e posteriormente submetidas a LC-ESI-MS/MS. A concentração média (±DP) de F encontrada no plasma dos camundongos foi de 0,023±0,010 e 0,019±0,007 mg/L para os animais do grupo controle, das linhagens A/J e 129P3/J, respectivamente, e de 0,151±0,043 e de 0,252±0,060 mg/L de F para os animais das linhagens A/J e 129P3/J, respectivamente, tratados com água contendo 50 mg/L de F. A ANOVA a 2 critérios revelou que houve diferença significativa entre os tratamentos (F= 658,0, p<0,0001), mas não entre as linhagens (F=3,3 p=0,075), tendo havido interação significativa entre estes critérios (F=16,50, p=0,0002). Já a concentração média (±DP) de F incorporado no esmalte dos incisivos dos camundongos foi 471,4±215,8 mg/kg e 151,7±58,8 mg/kg para os animais do grupo controle das linhagens 129P3/J e A/J, respectivamente, e 2711,2±1019,2 mg/kg, 1756,9±921,6 mg/kg para os animais das linhagens 129P3/J e A/J, respectivamente, tratados com água contendo 50 mg/L de F. A ANOVA a 2 critérios encontrou diferença significativa entre as linhagens (F=11,36, p=0,0016) e entre os tratamentos (F=103,50, p<0,0001), sem interação significativa entre ambos (F=2,82, p=0,1004). Os resultados proteômicos mostraram redução na abundância de proteínas no estágio de maturação, quando comparado com o de secreção. Foi observado que o tratamento com F aumentou consideravelmente o número de spots proteicos detectados em ambos os estágios, sendo que este aumento foi maior para os animais da linhagem A/J, indicando uma tentativa de se combater os efeitos deletérios do F e reforçando a maior susceptibilidade aos seus efeitos desta linhagem. A identificação das proteínas com expressão diferencial revelou que tanto a linhagem quanto o tratamento com F levaram à expressão diferencial de proteínas pertencentes a todas as categorias funcionais.
The mechanisms by which excessive ingestion of fluoride (F) during amelogenesis leads to fluorosis are still not precisely known. It has been shown that certain strains of mice are more susceptible to dental fluorosis than others, which turns these strains the ideal model for studying the molecular phenomena involved in this pathology. In the present study, we employed a proteomic approach to identify and evaluate changes in protein expression of secretory and maturation-stage enamel matrix in two strains of mice with different susceptibilities to dental fluorosis (A/J, susceptible and 129P3/J, resistant). Mice of both genders, from 129P3/J (n=200) and A/J (n=200) strains were divided into two groups for each strain. They received a low-F diet and drinking water containing 0 (control) or 50 mg/L F for 6 weeks. The F concentration was analyzed in plasma and enamel incisors. For proteomic analysis, the enamel matrix of secretory and maturation stages (incisors) was scrapped. For the extraction of enamel proteins, 1 ml of lysis buffer containing 7 M urea, 2 M thiourea, 4% CHAPS, 1% DTT, 0.5% ampholytes carriers pH 3-10 and a cocktail of protease inhibitors was added to 15 mg of enamel matrix powder. The enamel proteins extracted for each group were separated by two-dimensional electrophoresis and subsequently subjected to LC-ESIMS/ MS. The mean (± SD) F concentrations found in plasma were 0.023 ± 0.010 and 0.019 ±0.007 mg/L for the control group, A/J and 129P3/J strains, respectively; and 0.151 ± 0.043 and 0.252 ± 0.060 mg/L F for A/J and 129P3/J mice, respectively, treated with water containing 50 mg/L F. Two-way ANOVA revealed significant differences between treatments (F = 658.0, p <0.0001), but not between strains (F = 3.3 p = 0.075), with was significant interaction between these criteria (F = 16.50, p = 0.0002). The mean (± SD) F concentrations in the enamel of the incisors were 471.4 ± 215.8 mg/kg and 151.7 ± 58.8 mg/kg for the control group of 129P3/J and A/J strains, respectively; and 2711.2 ± 1019.2 mg/kg and 1756.9 ± 921.6 mg/kg for 129P3/J and A/J mice, respectively, treated with water containing 50 mg/L F. Two-way ANOVA detected significant differences between the strains (F=11.36, p=0.0016) and between treatments (F=103.50, p <0.0001), without significant interaction between these criteria (F=2.82, p=0.1004). The proteomic results revealed a reduction in the abundance of proteins in the maturation stage, as compared with the secretory stage. Treatment with F greatly increased the number of protein spots detected in both stages. This increase was greater for A/J mice, indicating an attempt to fight the deleterious effects of F and, thus, reinforcing the susceptibility of this strain to the effects of F. The identification of differentially expressed proteins revealed that both the strain and the treatment with F led to differential expression of proteins belonging to all functional categories.

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Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)
Formulações de dentifrícios com concentrações reduzidas de fluoreto (F) têm sido estudadas para diminuir o risco de fluorose dentária. O objetivo do trabalho foi avaliar a eficácia de dentifrícios com concentrações reduzidas de F (250 μgF/g), suplementados com hexametafosfato (HMP) sobre a desmineralização do esmalte de dente bovino. Blocos de esmalte foram submetidos a repetidas ciclagens de pH alternadas com tratamentos (2x/dia) com dentifrícios sem F contendo HMP nas concentrações de 0, 0,25, 0,5, 1,0, 2,0 e 3,0%, dentifrícios com 250 gF/g suplementados com HMP nas mesmas concentrações, placebo (sem F e HMP), um com 500 μgF/g, outro com 1100 μgF/g e um comercial (Crest, de 1100 gF/g). Após as ciclagens determinou-se a dureza de superfície final (SHf), perda integrada de dureza de subsuperfície (ΔKHN) e o conteúdo de F no esmalte. Os resultados foram submetidos à ANOVA e teste de Bonferroni (p<0.05). O grupo 250 gF/g com 0,5% de HMP apresentou maior valor de SHf, e menor ΔKHN, seguido do grupo de 250 gF/g com 1,0% de HMP que ficou semelhante ao 1100 gF/g e Crest. HMP não interferiu na incorporação de F pelo esmalte em concentrações menores que 3%. Além disso, a adição de 0,5% de HMP a um dentifrício sem F causou um aumento de SHf e uma redução de ΔKHN em comparação ao placebo. Conclui-se que é possível reduzir a concentração de F a 250 gF/g e se obter uma ação comparável de um dentifrício comercial sobre a desmineralização do esmalte bovino através da suplementação com hexametafosfato nas concentrações de 0,5 e 1%
Formulations of dentifrices with reduced concentrations of fluoride (F) have been studied to decrease the risk of dental fluorosis. The aim of this study was to evaluate the efficacy of dentifrices with low concentration of F (250 μgF/g), supplemented with hexametaphosphate (HMP) on the demineralization of bovine tooth enamel. Blocks of enamel were submitted to repeated pH cyclings alternated with treatments (2x/day) with dentifrices without F or containing 250 gF/g supplemented with HMP at concentrations of 0, 0,25, 0,5 1,0, 2,0 e 3,0%, dentifrices supplemented with HMP the same concentrations, placebo (without F and HMP), a dentifrice with 500 μgF/g, another with 1100 μgF/g and a commercial dentifrice (Crest, 1100 gF/g). After cycling, the following analysis were conducted: final surface hardness (SHf), subsurface hardness integrated loss (ΔKHN) and the content of F on enamel. The results were submitted to variance analysis and Bonferroni test (p<0.05). The group of 250 gF/g with 0,5% HMP showed the highest SHf value and the lowest ΔKHN value, followed by the group supplemented with 1,0% HMP which was similar to 1100 gF/g and Crest groups. HMP did not impair the uptake of F by enamel at concentrations lower than3%. Furthermore the addition of 0,5% HMP to a non fluoridated dentifrice caused a rise on SHf and a decrease on ΔKHN in comparison to placebo. It was concluded that it is possible to reduce the concentration of F to 250 μgF/g and obtain an action similar to a commercial dentifrice on the demineralization of enamel by supplementation with hexametaphosphate in concentrations of 0.5 and 1%

Orientadores: Raquel Fernanda Gerlach, Frederico Barbosa de Sousa
Tese (doutorado) - Universidade Estadual de Campinas, Faculdade de Odontologia de Piracicaba
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Resumo: O esmalte é o tecido mais mineralizado do corpo. Esta característica o torna um tecido altamente conservado no período post mortem. Por isso ele é citado como o melhor tecido para se estudar matéria orgânica em fósseis no campo da antropologia, paleontologia e arqueologia. É possível também a determinação do sexo na ciência forense. Porém a dificuldade está em se extrair o conteúdo orgânico destes dentes, já que o esmalte maduro contém menos de 1% de proteínas. Dois estudos da presente tese descrevem um método muito eficiente em extrair proteínas do esmalte. Esta mineralização do esmalte dentário pode ser prejudicada por doenças, como a fluorose dentária por exemplo. Em nosso terceiro estudo, analisamos o perfil dos aminoácidos para saber se o flúor interfere na clivagem das amelogeninas. Neste estudo, a clivagem da amelogenina não é afetada pelo flúor em dentes humanos fluoróticos erupcionados e inclusos. O quarto estudo traz como hipótese que a distribuição espacial dos conteúdos bioquímicos nas lesões fluoróticas do esmalte se assemelha aquela observada na última onda de mineralização durante o estágio de maturação. Observou-se neste estudo que há um aumento do conteúdo orgânico e uma hipomineralização na superfície no esmalte fluorótico, tanto nos terceiros molares erupcionados quanto inclusos. Estes dados sugerem que a lesões fluoróticas em esmalte humano refletem a composição do esmalte no período tardio de maturação da amelogênese
Abstract: The dental enamel is the most highly mineralized tissue in the body. Due to its characteristics, the enamel is highly inert to changes brought about by time and the environment, being a very important source of information for palaeo-, palaeanthropo-, and anthropologists. The enamel proteins are also used for sex identification in forensic science. But protein recovery from the enamel it is a challenging task. Here, we present two studies that describe procedures very effective in providing enamel samples that are adequate for protein analysis. This mineralization could be impaired by diseases like dental fluorosis, for example. In the third study, we analyzed the amino acid profile in the erupted and nonerupted fluorotic human teeth compared to control ones. In this study the cleavage of amelogenin was not affected by fluoride in the fluorotic teeth. In the fourth study we hypothesized that the composition of fluorotic lesions may resemble the enamel found during last wave of enamel mineralization. We found an increase in the organic content and a superficial hypomineralization of the fluorotic enamel, in both erupted and non-erupted human third molars. These data suggest that in both non-erupted and erupted human teeth the fluorotic lesions resembles the late maturation stage enamel, which is not mineralized until maturation is completed
Doutorado
Histologia e Embriologia
Doutor em Biologia Buco-Dental

Studies into the behavioral ecology of wild boar and domestic pigs are promising, yet largely neglected, areas of archaeozoological research. Changes in both the diet and health of animals may reflect specific details about the possible scale and extent of human impact on hunted wild boar populations and domesticated pigs in the past. Histological and chemical ‘signatures’ of (for example) physiological stress, brought about by possible human influence, can often be recovered in the dental and skeletal tissues of Sus. However, a fuller interpretation of what the significance of these signatures might be can only be achieved if their aetiology is known, and that can only be done by studying these phenomena in modern extant populations. One of the many aspects of the human–Sus relationship is the exposure of wild boar to contaminants from anthropogenic sources. An example of this is the pollution of wild boar habitats by fluoride from power plants and other emission sources, leading to the occurrence of characteristic dental changes, known as dental fluorosis, in the affected individuals of Sus scrofa (Kierdorf et al. 2000). However, dental fluorosis also occurs in wild and domestic mammals (and in humans) living in areas with increased environmental levels of fluoride from natural sources (Shupe et al. 1983; Cronin et al. 2000, 2003; Garrott et al. 2002; WHO 2002). The macroscopic changes of dental fluorosis reflect a disturbance of the processes involved in enamel formation. Once the permanent dentition of an individual is fully formed, exposure to excess levels of fluoride will not lead to fluorotic enamel changes. Dental fluorosis can therefore be used as a highly sensitive indicator of excess fluoride exposure during the period of tooth formation in humans and other mammals (Fejerskov et al. 1988; DenBesten 1994; Boulton et al. 1999; Kierdorf & Kierdorf 1999; Kierdorf et al. 1999). Higher levels of fluoride also exert negative effects on the skeleton throughout the life of an individual, the pathological changes being known as skeletal fluorosis (WHO 2002). This crippling disability is a major human health problem in various regions of Africa, China, and the Indian subcontinent, where millions of people are affected (Finkelman et al. 1999; WHO 2002).

Fluoride has made an enormous contribution to declines in dental caries (Kidd 2005; Murray and Naylor 1996). Fissure sealants are a proven preventive agent. This chapter provides a brief overview of the history of fluoride and presents a brief synopsis of the mode of action, method of delivery, safety, and controversies in the use of fluoride. A public health perspective on fissure sealants will also be presented. An account of the history of fluoride can be found in Kidd (2005) and Murray et al. (2003) and is summarized in this section (see Box 12.1 for key dates). In 1901, Frederick McKay, a dentist in Colorado Springs, USA, noticed that many of his patients, who had spent all their lives in the area, had a distinctive stain on their teeth known locally as ‘Colorado stain’. McKay was puzzled and called in the assistance of a dental researcher G.V. Black. They found that other communities in the USA had the characteristic mottling. Their histological examination of affected teeth showed that the enamel was imperfectly calcified, but that decay in the mottled teeth was no higher than in normal teeth. McKay suspected that something in the water supply was producing the brown stain, and more evidence came from Bauxite, a community formed to house workers of a subsidiary of the Aluminium Company of America (ALCOA). A local dentist noticed that children in Bauxite had mottled teeth, whereas children in nearby Benton did not. McKay investigated the problem but was unable to find a cause for the staining when the water supply was tested. In 1933, Mr H.V. Churchill, Chief Chemist for ALCOA (anxious that aluminium would not be blamed for the mottling), analysed the water and found that the fluoride ion concentration in the water supply of the Bauxite community was abnormally high (13.7 ppm). He tested other communities affected by mottling which had been previously identified by McKay and found that they too had high levels of fluoride present in the water supplies.

The aim of this chapter is to cover the management of more complicated clinical problems associated with children and adolescents: tooth discolouration, inherited enamel and dentine defects, hypodontia, and tooth surface loss. As there is considerable overlap in the application of the various restorative techniques, the chapter is divided into two parts. The first outlines the clinical steps involved in the various procedures, while the second covers the more general principles of management of particular dental problems. It is not the remit of this chapter to cover advanced restorative dentistry in detail, but many of the techniques and indications used in children are the same as those for adults (Boxes 11.1 and 11.2). With the aid of some clinical examples, eight of the restorative procedures will be described in simple stages. Omitted from this list are the stages involved in the provision of full crown restorations and bridgework, which are the specific remit of a restorative dentistry textbook. However, the provision of porcelain veneers, more commonly associated with adult patients, will be mentioned briefly. This technique involves the daily placement of carbamide peroxide gel into a custom-fitted tray on either the upper or the lower arch. As the name suggests, it is carried out by the patient at home and is initially done on a daily basis. • Mild fluorosis. • Moderate fluorosis as an adjunct to hydrochloric acid–pumice micro-abrasion. • Yellowing of ageing. • Single teeth with sclerosed pulp chambers and canals. • Selective bleaching for aesthetic purposes. • Upper impression and working model. • Soft mouthguard—avoiding the gingival tissues. • 10% carbamide peroxide gel. 1. Take an alginate impression of the arch to be treated and cast a working model in stone. 2. Relieve the labial surfaces of the teeth by about 0.5mm and make an acrylic pull-down vacuum-formed splint as a mouthguard with or without reservoirs for bleaching agent on the teeth requiring lightening. The splint should be no more than 2mm thick and should not cover the gingival tissues. It is only a vehicle for the bleaching gel and is not intended to protect the gingivae.